Rita Is Charged with Murder and Pleads Diminished Responsibility

Rita is charged with murder and pleads diminished responsibility. Where does the burden lie in respect of the defence and what is the relevant standard of proof?

A) The prosecution bears the burden of disproving diminished responsibility beyond reasonable doubt
B) The prosecution bears the burden of disproving diminished responsibility on a balance of probabilities
C) Rita bears the burden of proving diminished responsibility beyond reasonable doubt
D) Rita bears the burden of proving diminished responsibility on a balance of probabilities